On Mon, 2012-08-13 at 22:39 +0800, Peng Tao wrote:
> For buffer write, use policy based mechanism to determine layoutget size.
> Currently files use whole file layout, objects use offset-to-isize, and
> blocks search next hole in inode mapping and use offset-to-hole.
>
> For direct write, just use dreq->bytes_left.
>
> Signed-off-by: Peng Tao <tao.peng@xxxxxxx>
> ---
> fs/nfs/blocklayout/blocklayout.c | 1 +
> fs/nfs/direct.c | 7 +++++
> fs/nfs/internal.h | 1 +
> fs/nfs/nfs4filelayout.c | 1 +
> fs/nfs/objlayout/objio_osd.c | 3 +-
> fs/nfs/pnfs.c | 51 +++++++++++++++++++++++++++++++++++++-
> fs/nfs/pnfs.h | 13 +++++++++
> 7 files changed, 75 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
> index 1093968..c4215cf 100644
> --- a/fs/nfs/blocklayout/blocklayout.c
> +++ b/fs/nfs/blocklayout/blocklayout.c
> @@ -1240,6 +1240,7 @@ static const struct nfs_pageio_ops bl_pg_write_ops = {
> static struct pnfs_layoutdriver_type blocklayout_type = {
> .id = LAYOUT_BLOCK_VOLUME,
> .name = "LAYOUT_BLOCK_VOLUME",
> + .flags = PNFS_LAYOUTGET_SEARCH_HOLE,
> .read_pagelist = bl_read_pagelist,
> .write_pagelist = bl_write_pagelist,
> .alloc_layout_hdr = bl_alloc_layout_hdr,
> diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
> index c39f775..c1899dd 100644
> --- a/fs/nfs/direct.c
> +++ b/fs/nfs/direct.c
> @@ -46,6 +46,7 @@
> #include <linux/kref.h>
> #include <linux/slab.h>
> #include <linux/task_io_accounting_ops.h>
> +#include <linux/module.h>
>
> #include <linux/nfs_fs.h>
> #include <linux/nfs_page.h>
> @@ -191,6 +192,12 @@ static void nfs_direct_req_release(struct nfs_direct_req *dreq)
> kref_put(&dreq->kref, nfs_direct_req_free);
> }
>
> +ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq)
> +{
> + return dreq->bytes_left;
> +}
> +EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left);
> +
> /*
> * Collects and returns the final error value/byte-count.
> */
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 31fdb03..e68d329 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -464,6 +464,7 @@ static inline void nfs_inode_dio_wait(struct inode *inode)
> {
> inode_dio_wait(inode);
> }
> +extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
>
> /* nfs4proc.c */
> extern void __nfs4_read_done_cb(struct nfs_read_data *);
> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
> index 53f94d9..f81edd7 100644
> --- a/fs/nfs/nfs4filelayout.c
> +++ b/fs/nfs/nfs4filelayout.c
> @@ -1289,6 +1289,7 @@ filelayout_get_ds_info(struct inode *inode)
> static struct pnfs_layoutdriver_type filelayout_type = {
> .id = LAYOUT_NFSV4_1_FILES,
> .name = "LAYOUT_NFSV4_1_FILES",
> + .flags = PNFS_LAYOUTGET_ALL_FILE,
> .owner = THIS_MODULE,
> .alloc_layout_hdr = filelayout_alloc_layout_hdr,
> .free_layout_hdr = filelayout_free_layout_hdr,
> diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
> index ea6d111..e487fb8 100644
> --- a/fs/nfs/objlayout/objio_osd.c
> +++ b/fs/nfs/objlayout/objio_osd.c
> @@ -638,7 +638,8 @@ static struct pnfs_layoutdriver_type objlayout_type = {
> .id = LAYOUT_OSD2_OBJECTS,
> .name = "LAYOUT_OSD2_OBJECTS",
> .flags = PNFS_LAYOUTRET_ON_SETATTR |
> - PNFS_LAYOUTRET_ON_ERROR,
> + PNFS_LAYOUTRET_ON_ERROR |
> + PNFS_LAYOUTGET_ISIZE,
>
> .alloc_layout_hdr = objlayout_alloc_layout_hdr,
> .free_layout_hdr = objlayout_free_layout_hdr,
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index 2e00fea..d1da23a 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -29,6 +29,7 @@
>
> #include <linux/nfs_fs.h>
> #include <linux/nfs_page.h>
> +#include <linux/pagevec.h>
> #include <linux/module.h>
> #include "internal.h"
> #include "pnfs.h"
> @@ -1172,19 +1173,67 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
> }
> EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
>
> +/*
> + * Return the number of contiguous bytes for a given inode
> + * starting at page frame idx.
> + */
> +static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
> +{
> + struct address_space *mapping = inode->i_mapping;
> + pgoff_t end;
> +
> + /* Optimize common case that writes from 0 to end of file */
> + end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
> + if (end != NFS_I(inode)->npages) {
> + rcu_read_lock();
> + end = radix_tree_next_hole(&mapping->page_tree, idx + 1, ULONG_MAX);
> + rcu_read_unlock();
> + }
> +
> + if (!end)
> + return i_size_read(inode) - (idx << PAGE_CACHE_SHIFT);
> + else
> + return (end - idx) << PAGE_CACHE_SHIFT;
> +}
> +
> void
> pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
> {
> + u64 wb_size;
> + unsigned policy = NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->flags &
> + PNFS_LAYOUTGET_POLICY_MASK;
> +
> BUG_ON(pgio->pg_lseg != NULL);
>
> if (req->wb_offset != req->wb_pgbase) {
> nfs_pageio_reset_write_mds(pgio);
> return;
> }
> +
> + if (pgio->pg_dreq == NULL) {
> + switch(policy) {
> + case PNFS_LAYOUTGET_ISIZE:
> + wb_size = i_size_read(pgio->pg_inode) - req_offset(req);
> + break;
> + case PNFS_LAYOUTGET_SEARCH_HOLE:
> + wb_size = pnfs_num_cont_bytes(pgio->pg_inode, req->wb_index);
> + break;
> + case PNFS_LAYOUTGET_ALL_FILE:
> + wb_size = NFS4_MAX_UINT64;
> + break;
> + default:
> + WARN_ONCE(1, "invalid layoutget policy %u", policy);
> + wb_size = PAGE_CACHE_SIZE;
> + break;
> + }
> + } else {
> + wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
> + }
> +
Please just calculate the correct value for wb_size inside
bl_pg_init_write(), and pass it as an extra parameter to
pnfs_generic_pg_init_write().
Then add pnfs_pg_init_object_write for objects, that calls the modified
pnfs_generic_pg_init_write() with the PNFS_LAYOUTGET_ISIZE value.
Files don't call this function, so adding the PNFS_LAYOUTGET_ALL_FILE
isn't needed.
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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